'City-killer' asteroid whizzes past Earth, catching scientists by surprise

Posted at 2:45 PM, Jul 26, 2019
and last updated 2019-07-26 17:45:03-04

(KGTV) — An asteroid whizzed by Earth this week closer than our distance from the moon and with enough force to level a city, scientists say.

Asteroid 2019 OK careened past our planet Wednesday about 45,000 miles away and inside Earth's orbit with the moon, according to the International Astronomical Union.

The asteroid was discovered this week by astronomy teams in Brazil and the U.S. before it made its pass by Earth. It measures an estimated 187 to 426 feet, or 57 to 130 meters, across, enough to be deemed a "city-killer" by scientists.

“It would have gone off like a very large nuclear weapon,” Alan Duffy, a lead scientist for the Royal Institution of Australia, told the Washington Post. “Many megatons, perhaps in the ballpark of 10 megatons of TNT, so something not to be messed with.”

Despite the potentially catastrophic impact 2019 OK could have wrought, it wouldn't cause a global event.

“It snuck up on us pretty quickly,” said Michael Brown, a Melbourne-based observational astronomer, told the Post. “People are only sort of realizing what happened pretty much after it’s already flung past us.”

So how did observers miss the "city-killer" asteroid?

Scientists say the size of the asteroid was nowhere near those capable of causing an extinction-level event. More than 90% of those asteroids have been identified by NASA.

The asteroid's speed and orbit were also a factor, scientists say. An elliptical orbit didn't allow the asteroid to spend a lot of time near Earth and it traveled at about 54,000 mph, a higher than average speed.

NASA is currently working on methods of deflecting harmful asteroids, involving pushing the objects off their trajectory toward Earth in various ways.